Clean up ApiQueryImageInfo continuation
Reviewing this code, I spotted a few issues:
* 'imagerepository' is added to non-images, and to images that were
skipped this round due to iicontinue. The latter is particularly
troublesome, as clients may wind up with an incorrect value when
merging continued results.
* Say two images are being queried, A.jpg and B.jpg. If the query needs
to be continued somewhere in the middle of A.jpg's old versions, but
then A.jpg is deleted before the client sends the continuation query,
it will start in the middle of B.jpg's old versions instead of at the
beginning of B.jpg's revisions.
* If the query needs to be continued somewhere in the middle of A.jpg's
old versions, but in the continuation query some other module that is
also being continued fills the result object, iicontinue will be
reset to the *beginning* of A.jpg's old versions instead of preserving
the position in the middle.
Change-Id: I08e2941010c7a70ff90b6244bfddd5ed0540fc9f